Key points:

Banks still under pressure from APRA to slow interest-only lending and raise more capital

The new rates affect a variety of fixed-rate mortgages — both for owner occupier and investors — with some of the rises of 0.5 percentage points, double the standard move from the Reserve Bank.

The bank emailed mortgage brokers to inform them that the new rates would become effective immediately.

Fixed rates for owner-occupier home loan customers making interest only repayments have been increased by 0.25 percentage points, while fixed interest-only rates for investors on two-to-five year terms have been raised by 0.5 percentage points.

One-year fixed rates for interest-only investment loans and longer term loans, making principal and interest repayments, have been raised by 0.25 percentage points as well.

Fixed rates for owner-occupier customers making principal and interest repayments and standard variable rates have not changed.

In a brief statement the bank said it was raising rates again "to ensure we continue to meet our regulatory requirements".

"Home loan customers who already have a fixed rate loan are unaffected by these changes," the bank said.

Banks still under pressure to slow lending and raise capital

While the annualised growth in investor lending came in at 6.7 per cent in February — below APRA's 10 per cent speed limit — the regulator still stiffened the rules limiting interest-only loans to 30 per cent of new residential mortgage loans and tightening limits on loan-to-value ratios.

Up until APRA's intervention, investor loans were taking up around 40 per cent of new mortgages approved by the banks.

UBS bank analyst Jonathon Mott said cutting interest-only loans from 40 to 30 per cent of new loans would reduce new mortgages by around $15 billion per year and the "Big Four" banks' profitability by around 1 per cent.

Peter Marshall, from the rate comparison website Mozo, said targeting fixed-term loans was becoming increasingly popular with the banks, as they only affected new and prospective customers.

The CBA, along with virtually every other home lender, started a fresh round of out-of-cycle rate hikes last month.

"It doesn't surprise me you are now starting to see some bigger rate movements," Mr Marshall said.

"Rates are expected to go up in the medium term at least, so the banks are factoring that in and building it into their fixed rates," he said.

Increasing rates at the longer end also allows banks to raise term deposits to attract new business and stabilise their funding in a very competitive market.